In the information age, portable electronic computing devices, such as note-book computer, lap top computer, hand-held computer, palm book and palm phone etc, have become more and more popular around the world. Internet, wire-less communication, multi-media and nano-semiconductor technologies as well as the variety of software applications are boosting those computing devices with the viewing terminal more vigorously in the new century.
Currently used portable computers are based on the direct-view display technology where the angle between the display panel and the key board panel is always equal or larger than right angle during operation; and the back-lit panel is always attached behind of the display panel. Such computer has the following disadvantages.                1. Ambient light interference. Most computers are not suitable for outdoor applications due to the sun shine wash-out effect. The intensity of the incident sunlight can be many times more than the luminance of the display's back lighting. The intensity of the surface reflection of the sunlight is so high, for example, more than 200 nits, that it will substantially wash-out the displays image. In the indoor environment, on the other hand, the ambient light impinged on the screen causes surface reflection (glare) and degrades the contrast ratio of the display.        2. The back-lit panel attached behind the display panel is the major consumption of the power. Generally, more than half of the electric energy of a computer is consumed by the back-lit system, which requires a bulky battery structure to ensure a predetermined operation time. In the out door application particularly, the battery and the thermo sink structure are so heavy, which makes the portable computing devices impractical.        3. Spatial limitation. While traveling, users often find that it's very inconvenient to operate their computers due to the limitation of space. Sitting in a normal class seat of an airplane, the passenger seat of a car, or a bus, the compact space between front and back chairs restrains the computer in the direct view position where the open angle of the display screen is limited by the tilted back of the front chair.        4. Less privacy. The computer screen is always open to the side-viewers. With the viewing angle of the display is getting larger and larger, people tend to use the viewing angle narrower technology to keep their privacy.        
In a word, the traditional direct-view structure of the computer has many limitations in its applications.